Roller bearings with cylindrical, tapered or spherical rollers are composed of inner and outer rings with a complement of rollers usually spaced apart with a cage therebetween. Many designs of roller bearings have grooves or ribs or flanges on at least one of the rings to define a raceway which guides the tracking of the rolling motion of the rollers as the rings rotate relative to one another. Modifications of the shape or profile of the rollers can improve the performance of the bearings under thrust load.